Get the return value of an asychronous operation
The return value is set when the operation is complete or safe, whichever comes first.
@pre The operation is safe or complete
@note BUG: complete callback may never be called when the safe message is received before the complete message
@param c async operation to inspect @returns return value of the operation
See Implementation
Get the return value of an asychronous operation
The return value is set when the operation is complete or safe, whichever comes first.
@pre The operation is safe or complete
@note BUG: complete callback may never be called when the safe message is received before the complete message
@param c async operation to inspect @returns return value of the operation